Expert: Rob Painter - 7/28/2009

Question
QUESTION: I have a 2003 Cadillac Cts the interior lights dont work, the keyless entry don't work, and how the car lights suppose to come on when you open the door dont work unless you cut them on manual. The cigarette lights stays on which seem to be draining the battery. Do you happen to know where the exterior light relay may be


ANSWER: Hello,

You need to look at your owners manual. The first thing I would be looking at the fuses to see if the cigarette lighter popped the dome/door lock fuses. Your manual will tell you the location of all relays and fuses.

Rob

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QUESTION: Would this be causing the battery to go dead. My car seems to die overnight or when it sits more than 6 hours a time. I have replaced the batttery and alternator.

ANSWER: Hello,

You have fallen into the common trap of chasing ghosts by replacing the battery and alternator and still having the same problem. Guessing is expensive!

Get a test light or meter. Disconnect positive cable. Hook meter or test light between cable and battery terminal. If light is real bright or meter says 12v, you have a parasitic draw. Now, remove each fuse and replace one at a time until test light goes out or no reading on meter. That is your problem circuit. Now, you need to determine what is on that circuit to find the exact cause. Just an example-door locks and dome light might be on same circuit. The exact cause needs to be seperated from there. One of the most common problems I run across is bad cigarette lighter elements. In this case, disconnect the lighter and be done with it or replace.

Rob

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QUESTION: WHAT ALL DO THE ELECTRIC BODY MODULE CONTROL. COULD A FAULT EBMC CAUSE THESE PROBLEMS. EXTERIOR LIGHT DONT FUNCTION WHEN OPEN DRIVER DOOR, BUT COMES ON WHEN THE OTHER THREE DOORS ARE OPEN,  RADIO DO NOT CUT OFF WHEN DRIVER DOOR IS OPEN BUT CUT OFF WHEN OTHER THREE DOORS ARE OPEN. COULD THIS BE THE EBMC

Answer
Hello,

Yes the body control module can be bad, but what if you replace that and that is not your problem? This car can turn into a money funnel quickly if you keep guessing. Do as I suggest. Have the vehicle professionally diagnosed. There are far too many problems that can cause the same symptoms.

Rob